#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using pii = pair<int, int>;

const int MAXN = 5010;
const int MOD = 1e9+7;

int n, m;
ll s, a[MAXN], sum[MAXN];   


int main()
{
#ifdef LOCAL
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
#endif
    ios::sync_with_stdio(false), cin.tie(0);
    cin >> n >> m >> s;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = n; i >= 1; i--) sum[i] = sum[i+1]+a[i];

    int r = n;
    double res = 0;
    while (r >= 1 && s) {
        int p = 0;
        double temp = 0;

        for (int i = r; i >= 1; i--) {
            double d = (sum[i] - sum[r+1]) * 1.0 / (r+1-i);
            if (d > temp) temp = d, p = i;
        }

        ll ss = min(s, 1ll*m*(r-p+1));
        s -= ss;
        res += temp*ss;
        r = p - 1;
    }

    printf("%.6lf\n", res);
    return 0;
}